9 year old won’t stop scratching

Guys 😩 this is my 9 year old girl Zoey. Now all her life she’s had some skin issues but not this bad. All she does all day is scratch & itch until the skin is bleeding. I’ve tried oatmeal baths, a dog anti itch shampoo, giving Benadryl. I don’t know what to do anymore I hate seeing her like this please help